.

Comentarios

VB.NET

'Single line only

Rem Single line only

C#

// Single line

/* Multiple

line */

/// XML comments on single line

/** XML comments on multiple lines */

Esctructura del programa

VB.NET

Imports System

Namespace MyNameSpace

  Class HelloWorld

    'Entry point which delegates to C-style main Private Function

    Public Overloads Shared Sub Main()

      Main(System.Environment.GetCommandLineArgs())

    End Sub

  Overloads Shared Sub Main(args() As String)

    System.Console.WriteLine("Hello World")

  End Sub 'Main

  End Class 'HelloWorld End Namespace 'MyNameSpace

C#

using System

Namespace MyNameSpace

{

  class HelloWorld

  {     

    static void Main(string[] args)

    {

      System.Console.WriteLine("Hello World")

    }

  }

}

Tipos de datos

VB.NET

'Value Types

Boolean

Byte

Char (example: "A")

Short, Integer, Long

Single, Double

Decimal

Date

'Reference Types

Object

String

Dim x As Integer

System.Console.WriteLine(x.GetType())

System.Console.WriteLine(TypeName(x))

'Type conversion

Dim d As Single = 3.5

Dim i As Integer = CType (d, Integer)

i = CInt (d)

i = Int(d)

C#

//Value Types

bool

byte, sbyte

char (example: 'A')

short, ushort, int, uint, long, ulong

float, double

decimal

DateTime

//Reference Types

object

string

int x;

Console.WriteLine(x.GetType())

Console.WriteLine(typeof(int))

//Type conversion

float d = 3.5;

int i = (int) d

Constantes

VB.NET

Const MAX_AUTHORS As Integer = 25

ReadOnly MIN_RANK As Single = 5.00

C#

const int MAX_AUTHORS = 25;

readonly float MIN_RANKING = 5.00;

Enumeraciones

VB.NET

Enum Action

  Start

  'Stop is a reserved word

[Stop]

  Rewind

  Forward

End Enum

Enum Status

   Flunk = 50

   Pass = 70

   Excel = 90

End Enum

Dim a As Action = Action.Stop

If a <> Action.Start Then _

'Prints "Stop is 1"

   System.Console.WriteLine(a.ToString & " is " & a)

'Prints 70

System.Console.WriteLine(Status.Pass)

'Prints Pass

System.Console.WriteLine(Status.Pass.ToString())

Enum Weekdays

   Saturday

   Sunday

   Monday

   Tuesday

   Wednesday

   Thursday

   Friday

End Enum 'Weekdays

C#

enum Action {Start, Stop, Rewind, Forward};

enum Status {Flunk = 50, Pass = 70, Excel = 90};

Action a = Action.Stop;

if (a != Action.Start)

//Prints "Stop is 1"

  System.Console.WriteLine(a + " is " + (int) a);

// Prints 70

System.Console.WriteLine((int) Status.Pass);

// Prints Pass

System.Console.WriteLine(Status.Pass);

enum Weekdays

{

  Saturday, Sunday, Monday, Tuesday, Wednesday, Thursday, Friday

}

Operadores

VB.NET

'Comparison

=  <  >  <=  >=  <>

'Arithmetic

+  -  *  /

Mod

\  (integer division)

^  (raise to a power)

'Assignment

=  +=  -=  *=  /=  \=  ^=  <<=  >>=  &=

'Bitwise

And  AndAlso  Or  OrElse  Not  <<  >>

'Logical

And  AndAlso  Or  OrElse  Not

'String Concatenation

&

C#

//Comparison

==  <  >  <=  >=  !=

//Arithmetic

+  -  *  /

%  (mod)

/  (integer division if both operands are ints)

Math.Pow(x, y)

//Assignment

=  +=  -=  *=  /=   %=  &=  |=  ^=  <<=  >>=  ++  --

//Bitwise

&  |  ^   ~  <<  >>

//Logical

&&  ||   !

//String Concatenation

+

Disyunciones

VB.NET

greeting = IIf(age < 20, "What's up?", "Hello")

'One line doesn't require "End If", no "Else"

If language = "VB.NET" Then langType = "verbose"

'Use: to put two commands on same line

If x <> 100 And y < 5 Then x *= 5 : y *= 2  

'Preferred

If x <> 100 And y < 5 Then

  x *= 5

  y *= 2

End If

'or to break up any long single command use _

If henYouHaveAReally < longLine And _

itNeedsToBeBrokenInto2   > Lines  Then _

  UseTheUnderscore(charToBreakItUp)

If x > 5 Then

  x *= y

ElseIf x = 5 Then

  x += y

ElseIf x < 10 Then

  x -= y

Else

  x /= y

End If

'Must be a primitive data type

Select Case color   

  Case "black", "red"

    r += 1

  Case "blue"

    b += 1

  Case "green"

    g += 1

  Case Else

    other += 1

End Select

C#

greeting = age < 20 ? "What's up?" : "Hello";

if (x != 100 && y < 5)

{

  // Multiple statements must be enclosed in {}

  x *= 5;

  y *= 2;

}

if (x > 5)

  x *= y;

else if (x == 5)

  x += y;

else if (x < 10)

  x -= y;

else

  x /= y;

//Must be integer or string

switch (color)

{

  case "black":

  case "red":    r++;

   break;

  case "blue"

   break;

  case "green": g++;  

   break;

  default:    other++;

   break;

}

Bucles

VB.NET

'Pre-test Loops:

While c < 10

  c += 1

End While Do Until c = 10

  c += 1

Loop

'Post-test Loop:

Do While c < 10

  c += 1

Loop

For c = 2 To 10 Step 2

  System.Console.WriteLine(c)

Next

'Array or collection looping

Dim names As String() = {"Steven", "SuOk", "Sarah"}

For Each s As String In names

  System.Console.WriteLine(s)

Next

C#

//Pre-test Loops: while (i < 10)

  i++;

for (i = 2; i < = 10; i += 2)

  System.Console.WriteLine(i);

//Post-test Loop:

do

  i++;

while (i < 10);

// Array or collection looping

string[] names = {"Steven", "SuOk", "Sarah"};

foreach (string s in names)

  System.Console.WriteLine(s);

Matrices

VB.NET

Dim nums() As Integer = {1, 2, 3}

For i As Integer = 0 To nums.Length - 1

  Console.WriteLine(nums(i))

Next

'4 is the index of the last element, so it holds 5 elements

Dim names(4) As String

names(0) = "Steven"

'Throws System.IndexOutOfRangeException

names(5) = "Sarah"

'Resize the array, keeping the existing

'values (Preserve is optional)

ReDim Preserve names(6)

Dim twoD(rows-1, cols-1) As Single

twoD(2, 0) = 4.5

Dim jagged()() As Integer = { _

  New Integer(4) {}, New Integer(1) {}, New Integer(2) {} }

jagged(0)(4) = 5

C#

int[] nums = {1, 2, 3};

for (int i = 0; i < nums.Length; i++)

  Console.WriteLine(nums);

// 5 is the size of the array

string[] names = new string[5];

names[0] = "Steven";

// Throws System.IndexOutOfRangeException

names[5] = "Sarah"

// C# can't dynamically resize an array.

//Just copy into new array.

string[] names2 = new string[7];

// or names.CopyTo(names2, 0);

Array.Copy(names, names2, names.Length);

float[,] twoD = new float[rows, cols];

twoD[2,0] = 4.5;

int[][] jagged = new int[3][] {

  new int[5], new int[2], new int[3] };

jagged[0][4] = 5;

Funciones

VB.NET

'Pass by value (in, default), reference

'(in/out), and reference (out)

Sub TestFunc(ByVal x As Integer, ByRef y As Integer,

ByRef z As Integer)

  x += 1

  y += 1

  z = 5

End Sub

'c set to zero by default

Dim a = 1, b = 1, c As Integer

TestFunc(a, b, c)

System.Console.WriteLine("{0} {1} {2}", a, b, c) '1 2 5

'Accept variable number of arguments

Function Sum(ByVal ParamArray nums As Integer()) As Integer

  Sum = 0

  For Each i As Integer In nums

    Sum += i

  Next

End Function 'Or use a Return statement like C#

Dim total As Integer = Sum(4, 3, 2, 1) 'returns 10

'Optional parameters must be listed last

'and must have a default value

Sub SayHello(ByVal name As String,

Optional ByVal prefix As String = "")

  System.Console.WriteLine("Greetings, " & prefix

& " " & name)

End Sub

SayHello("Steven", "Dr.")

SayHello("SuOk")

C#

// Pass by value (in, default), reference

//(in/out), and reference (out)

void TestFunc(int x, ref int y, out int z) {

  x++;

  y++;

  z = 5;

}

int a = 1, b = 1, c; // c doesn't need initializing

TestFunc(a, ref b, out c);

System.Console.WriteLine("{0} {1} {2}", a, b, c); // 1 2 5

// Accept variable number of arguments

int Sum(params int[] nums) {

  int sum = 0;

  foreach (int i in nums)

    sum += i;

  return sum;

}

int total = Sum(4, 3, 2, 1); // returns 10

/* C# doesn't support optional arguments/parameters.

Just create two different versions of the same function. */

void SayHello(string name, string prefix) {

  System.Console.WriteLine("Greetings, " + prefix + " " + name);

}

void SayHello(string name) {

  SayHello(name, "");

}

Manjeo de excepciones

VB.NET

Class Withfinally

   Public Shared Sub Main()

      Try

         Dim x As Integer = 5

         Dim y As Integer = 0

         Dim z As Integer = x / y

         Console.WriteLine(z)

      Catch e As DivideByZeroException

         System.Console.WriteLine("Error occurred")

      Finally

         System.Console.WriteLine("Thank you")

      End Try

   End Sub 'Main

End Class 'Withfinally

C#

class  Withfinally

{

  public static void Main()

  {

    try

    {

      int x = 5;

      int y = 0;

      int z = x/y;

      Console.WriteLine(z);

    }

    catch(DivideByZeroException e)

    {

      System.Console.WriteLine("Error occurred");

    }

    finally

    {

      System.Console.WriteLine("Thank you");

    }

  }

}

Namespaces

VB.NET

Namespace ASPAlliance.DotNet.Community

  ...

End Namespace

'or

Namespace ASPAlliance

  Namespace DotNet

    Namespace Community

      ...

    End Namespace

  End Namespace

End Namespace

Imports ASPAlliance.DotNet.Community

C#

namespace ASPAlliance.DotNet.Community {

  ...

}

// or

namespace ASPAlliance {

  namespace DotNet {

    namespace Community {

      ...

    }

  }

}

using ASPAlliance.DotNet.Community;

Clases / Interfaces

VB.NET

'Accessibility keywords

Public

Private

Friend

Protected

Protected Friend

Shared

'Inheritance

Class Articles

  Inherits Authors

  ...

End Class

Imports System

Interface IArticle

   Sub Show()

End Interface 'IArticle

 _

Class IAuthor

   Implements IArticle

   Public Sub Show()

      System.Console.WriteLine("Show() method Implemented")

   End Sub 'Show

   'Entry point which delegates to C-style main Private Function

   Public Overloads Shared Sub Main()

      Main(System.Environment.GetCommandLineArgs())

   End Sub

   Overloads Public Shared Sub Main(args() As String)

      Dim author As New IAuthor()

      author.Show()

   End Sub 'Main

End Class 'IAuthor

C#

//Accessibility keywords

public

private

internal

protected

protected internal

static

//Inheritance

class Articles: Authors {

  ...

}

using System;

interface IArticle

{

  void Show();

}

class IAuthor:IArticle

{

  public void Show()

  {

    System.Console.WriteLine("Show() method Implemented");

  }

  public static void Main(string[] args)

  {

    IAuthor author = new IAuthor();

    author.Show();

  }

}

Constructores / Destructores

VB.NET

Class TopAuthor

  Private _topAuthor As Integer

  Public Sub New()

    _topAuthor = 0

  End Sub

  Public Sub New(ByVal topAuthor As Integer)

    Me._topAuthor = topAuthor

  End Sub

  Protected Overrides Sub Finalize()

   'Desctructor code to free unmanaged resources

    MyBase.Finalize()

  End Sub

End Class

C#

class TopAuthor {

  private int _topAuthor;

  public TopAuthor() {

     _topAuthor = 0;

  }

  public TopAuthor(int topAuthor) {

    this._topAuthor= topAuthor

  }

  ~TopAuthor() {

    // Destructor code to free unmanaged resources.

    // Implicitly creates a Finalize method

  }

}

Objetos

VB.NET

Dim author As TopAuthor = New TopAuthor

With author

  .Name = "Steven"

  .AuthorRanking = 3

End With

author.Rank("Scott")

author.Demote() 'Calling Shared method

'or

TopAuthor.Rank()

Dim author2 As TopAuthor = author 'Both refer to same object

author2.Name = "Joe"

System.Console.WriteLine(author2.Name) 'Prints Joe

author = Nothing 'Free the object

If author Is Nothing Then _

  author = New TopAuthor

Dim obj As Object = New TopAuthor

If TypeOf obj Is TopAuthor Then _

  System.Console.WriteLine("Is a TopAuthor object.")

C#

TopAuthor author = new TopAuthor();

//No "With" construct

author.Name = "Steven";

author.AuthorRanking = 3;

author.Rank("Scott");

TopAuthor.Demote() //Calling static method

TopAuthor author2 = author //Both refer to same object

author2.Name = "Joe";

System.Console.WriteLine(author2.Name) //Prints Joe

author = null //Free the object

if (author == null)

  author = new TopAuthor();

Object obj = new TopAuthor(); 

if (obj is TopAuthor)

  SystConsole.WriteLine("Is a TopAuthor object.");

Estructuras

VB.NET

Structure AuthorRecord

  Public name As String

  Public rank As Single

  Public Sub New(ByVal name As String, ByVal rank As Single)

    Me.name = name

    Me.rank = rank

  End Sub

End Structure

Dim author As AuthorRecord = New AuthorRecord("Steven", 8.8)

Dim author2 As AuthorRecord = author

author2.name = "Scott"

System.Console.WriteLine(author.name) 'Prints Steven

System.Console.WriteLine(author2.name) 'Prints Scott

C#

struct AuthorRecord {

  public string name;

  public float rank;

  public AuthorRecord(string name, float rank) {

    this.name = name;

    this.rank = rank;

  }

}

AuthorRecord author = new AuthorRecord("Steven", 8.8);

AuthorRecord author2 = author

author.name = "Scott";

SystemConsole.WriteLine(author.name); //Prints Steven

System.Console.WriteLine(author2.name); //Prints Scott

Propiedades

VB.NET

Private _size As Integer

Public Property Size() As Integer

  Get

    Return _size

  End Get

  Set (ByVal Value As Integer)

    If Value < 0 Then

      _size = 0

    Else

      _size = Value

    End If

  End Set

End Property

foo.Size += 1

Imports System

Class [Date]

   Public Property Day() As Integer

      Get

         Return day

      End Get

      Set

         day = value

      End Set

   End Property

   Private day As Integer

   Public Property Month() As Integer

      Get

         Return month

      End Get

      Set

         month = value

      End Set

   End Property

   Private month As Integer

   Public Property Year() As Integer

      Get

         Return year

      End Get

      Set

         year = value

      End Set

   End Property

   Private year As Integer

   Public Function IsLeapYear(year As Integer) As Boolean

      Return(If year Mod 4 = 0 Then True Else False)

   End Function 'IsLeapYear

   Public Sub SetDate(day As Integer, month As Integer,

year As Integer)

      Me.day = day

      Me.month = month

      Me.year = year

   End Sub 'SetDate

End Class '[Date]

C#

private int _size;

public int Size {

  get {

    return _size;

  }

  set {

    if (value < 0)

      _size = 0;

    else

      _size = value;

  }

}

foo.Size++;

using System;

class Date

{

    public int Day{

        get {

            return day;

        }

        set {

            day = value;

        }

    }

    int day;

    public int Month{

        get {

            return month;

        }

        set {

            month = value;

        }

    }

    int month;

    public int Year{

        get {

            return year;

        }

        set {

            year = value;

        }

    }

    int year;

    public bool IsLeapYear(int year)

    {

        return year%4== 0 ? true: false;

    }

    public void SetDate (int day, int month, int year)

    {

        this.day   = day;

        this.month = month;

        this.year  = year;

    }

}

Delegados / Eventos

VB.NET

Delegate Sub MsgArrivedEventHandler(ByVal message

As String)

Event MsgArrivedEvent As MsgArrivedEventHandler

'or to define an event which declares a

'delegate implicitly

Event MsgArrivedEvent(ByVal message As String)

AddHandler MsgArrivedEvent, AddressOf My_MsgArrivedCallback

'Won't throw an exception if obj is Nothing

RaiseEvent MsgArrivedEvent("Test message")

RemoveHandler MsgArrivedEvent, AddressOf My_MsgArrivedCallback

Imports System.Windows.Forms

'WithEvents can't be used on local variable

Dim WithEvents MyButton As Button

MyButton = New Button

Private Sub MyButton_Click(ByVal sender As System.Object, _

  ByVal e As System.EventArgs) Handles MyButton.Click

  MessageBox.Show(Me, "Button was clicked", "Info", _

    MessageBoxButtons.OK, MessageBoxIcon.Information)

End Sub

C#

delegate void MsgArrivedEventHandler(string message);

event MsgArrivedEventHandler MsgArrivedEvent;

//Delegates must be used with events in C#

MsgArrivedEvent += new MsgArrivedEventHandler

  (My_MsgArrivedEventCallback);

//Throws exception if obj is null

MsgArrivedEvent("Test message");

MsgArrivedEvent -= new MsgArrivedEventHandler

  (My_MsgArrivedEventCallback);

using System.Windows.Forms;

Button MyButton = new Button();

MyButton.Click += new System.EventHandler(MyButton_Click);

private void MyButton_Click(object sender, System.EventArgs e) {

  MessageBox.Show(this, "Button was clicked", "Info",

    MessageBoxButtons.OK, MessageBoxIcon.Information);

}

Consola I/O

VB.NET

'Special character constants

vbCrLf, vbCr, vbLf, vbNewLine

vbNullString

vbTab

vbBack

vbFormFeed

vbVerticalTab

""

Chr(65) 'Returns 'A'

System.Console.Write("What's your name? ")

Dim name As String = System.Console.ReadLine()

System.Console.Write("How old are you? ")

Dim age As Integer = Val(System.Console.ReadLine())

System.Console.WriteLine("{0} is {1} years old.", name, age)

'or

System.Console.WriteLine(name & " is " & age & " years old.")

Dim c As Integer

c = System.Console.Read() 'Read single char

System.Console.WriteLine(c) 'Prints 65 if user enters "A"

C#

//Escape sequences

\n, \r

\t

\\

\

Convert.ToChar(65) //Returns 'A' - equivalent to Chr(num) in VB

// or

(char) 65

System.Console.Write("What's your name? ");

string name = SYstem.Console.ReadLine();

System.Console.Write("How old are you? ");

int age = Convert.ToInt32(System.Console.ReadLine());

System.Console.WriteLine("{0} is {1} years old.", name, age);

//or

System.Console.WriteLine(name + " is " + age + " years old.");

int c = System.Console.Read(); //Read single char

System.Console.WriteLine(c); //Prints 65 if user enters "A"

Ficheros I/O

VB.NET

Imports System.IO

'Write out to text file

Dim writer As StreamWriter = File.CreateText

  ("c:\myfile.txt")

writer.WriteLine("Out to file.")

writer.Close()

'Read all lines from text file

Dim reader As StreamReader = File.OpenText

  ("c:\myfile.txt")

Dim line As String = reader.ReadLine()

While Not line Is Nothing

  Console.WriteLine(line)

  line = reader.ReadLine()

End While

reader.Close()

'Write out to binary file

Dim str As String = "Text data"

Dim num As Integer = 123

Dim binWriter As New BinaryWriter(File.OpenWrite

  ("c:\myfile.dat"))

binWriter.Write(str)

binWriter.Write(num)

binWriter.Close()

'Read from binary file

Dim binReader As New BinaryReader(File.OpenRead

  ("c:\myfile.dat"))

str = binReader.ReadString()

num = binReader.ReadInt32()

binReader.Close()

C#

using System.IO;

//Write out to text file

StreamWriter writer = File.CreateText

  ("c:\\myfile.txt");

writer.WriteLine("Out to file.");

writer.Close();

//Read all lines from text file

StreamReader reader = File.OpenText

  ("c:\\myfile.txt");

string line = reader.ReadLine();

while (line != null) {

  Console.WriteLine(line);

  line = reader.ReadLine();

}

reader.Close();

//Write out to binary file

string str = "Text data";

int num = 123;

BinaryWriter binWriter = new BinaryWriter(File.OpenWrite

  ("c:\\myfile.dat"));

binWriter.Write(str);

binWriter.Write(num);

binWriter.Close();

//Read from binary file

BinaryReader binReader = new BinaryReader(File.OpenRead

  ("c:\\myfile.dat"));

str = binReader.ReadString();

num = binReader.ReadInt32();

binReader.Close();